Synthesis, carbonic anhydrase enzyme inhibition evaluations, and anticancer studies of sulfonamide based thiadiazole derivatives.

The sulfonamide-based thiadiazole derivatives (STDs) with different hydrophobic/hydrophilic substitutions were synthesized to investigate their potentials in carbonic anhydrase inhibition (CAI). The CAI activity of the STDs (4a-4h) and the mechanism of the inhibition kinetics were determined. STD 4f contained both methoxy and Cl groups at benzene ring in STD 4f showed the lowest IC50 value. The molecular docking study confirmed that STDs bind strongly with the active sites of the target protein PDBID 1V9E. With the help of Lineweaver-Burk plots, inhibition kinetics of PDBIR 1V9E protein with STDs were determined. Cytotoxicity was checked against human keratinocyte cell lines and the anticancer properties were determined against MCF-7 cell lines. The electrochemical method was used to investigate the binding study with DNA and CA enzymes. Anticancer studies showed that STDs have weak bonding ability to DNA and strong binding ability with CA. It is concluded that anticancer activity is through CAI rather than by DNA binding.